Process and mechanism for treating metals or metal alloys in a molten state



Dec. 10, 1940 s. JUNGHANS 2,224,303

PROCESS AND MECHANISM FOR TREATING METALS UR METAL ALLOYS IN A MOLTEN STATE Filed May 11, 1938 um I In warrior.-

I v I H9 Pate'ntedDec. 10, 1940 UNITED STATES PROCESS AND MECHANISM FOR TREATING METALS R METAL ALLOYS IN A MOLTEN STATE Siegfried Junghans, Stuttgart, Wurttemberg, Germany Application May 11, 1938, Serial No. 207,228

' In Germany June 26, 1937 v 12 Claims.

In treating metals or metal alloys, particularly in continuous processes where the molten metal is continuously delivered to a cooled mold (chill mold), out of which the solidified cast bar like- 3 wise emerges continuously, it is not only important that the speed at which the molten metal flows in shall have a quite definite ratio to the speed of solidification, but care must also be taken that the solidification shall occur as unio formly as possible, simultaneously that is, over the entire cross section oi. the casting. Now because with the previously known processes of this type a dissipation oi heat does occur through the intermediary oi the cooled chill mold walls, the 15 maximum prevailing temperature is generally about in the middle 0! the cross section oi the casting, where the molten metal flows in, and the solidification at the outer edge of the cast bar always occurs more quickly than in the center, 80 so that a fluid pipe occurs at this place, which solidifies later than the outer portion. Because of this however, variations may occur that un- Iavorably aiiect the uniformity of the structure of the completed casting, because the parts that 25 solidified later as a rule have a considerably coarser structure than those that solidified immediately; moreover, particularly with alloys, separation of the components may easily occur in the slowly solidifying portions.

Recognizing these facts, the invention proposes to regulate the temperature exactly, both from the outside and from the inside, in order that uniform solidification may be eifected over the entire cross section. Through this type of cool- .5 ing, which will in the following be designated as "cooling," whereby however the concept "cooling" is to be understood quite broadly, the solidiflcation process may be completely controlled; and, above everything, the occurrence of a fluid 40 pipe, with its disadvantageous accompanying phenomena, may be avoided.

In order to diminish this iormation of pipes as much as possible, which is of course also promoted by the downwardly flowing stream of moltenmetal, it has already been suggested that a catch-. ing or intercepting device be disposed below the nozzle through which the molten metal flows into the cooled mold, which device diverts the inflowing stream of molten metal from its downward direction, so that the inflowing molten metal is prevented from forming eddies in the fluid casting head, which promotes the tendency to form pipes. In spite of this, the solidification process can not be sumciently controlled over the entire cross section of the cast bar.

Now according to the essential characteristic of the invention, the said catching or intercepting device is just what is made use oi in order to effect cooling in the middle of the chill mold as well, in that this catching or intercepting device is namely itself so constructed that it can be'cooled. Even though the process is carried out particularly favorably in this manner, it is also possible to obtain cooling, and consequently to obtain uniform temperature regulation, through the entire cross section of the fluid casting head with-- I out this catching or intercepting device, in that cooling tubes, say, are sunk into the fluid casting head to the necessary depth.

When a catching or intercepting device is employed, it may be or a cup-like shape, for example. This cup may be constructed doublewalled, whereby a cooling medium is conducted through the intermediate space. However, because this cooling action must be exerted chiefly so on the molten metal which is already in the chill mold, it may be advantageous to form the cup so that the cooling action is exerted chiefly on its outside, while its inside is more or less shielded from the cooling action. This may be attained in 8 a simple manner by the inner walls 0! the cup being made less heat conductive than the outer walls. Finally, it is however also possible to provide the catching or intercepting device, by means of a multiple-wall construction, with a number of 80 chambers, 01' which the outer chambers may be cooled more, while the inner chambers may on the contrary be cooled less (or may even be heated), in order to protect the new'incoming molten metal from too great cooling; and, rather, 88 to maintain itsaiely at the requisite temperature until it leaves the catching or intercepting device. It is naturally not absolutely necessary with all these constructions that the catching or intercepting device be shaped like a cup; on the contrary, the same result may be attained by other shapes as well.

A few forms or construction oi the catching or intercepting device according to the invention are illustrated in the drawing; and I Figure l namely shows a first form of construc-' tion in vertical longitudinal section inside the chill mold, only the upper end of which is shown;

Figure 2 shows a second form of construction, likewise in vertical longitudinal section; however in this case, as in the illustrations following it, the chill mold is omitted Figures 3 to 11 show further iorms oi construction in similar sectional illustrations;

Figure 12 is a longitudinal section through still another form of construction; and

Figures 13, 14 and 15 are plan views of cups showing various arrangements of outflow channels,

In the form of construction according to Figure 1, the fluid melt is delivered through the nozzle I into the chill mold 2, which is provided with a cooling jacket 3. The fluid head I is first formed inside the chill mold, and in solidifying it forms the bar 5. Below the outlet'of the nozzle I there is disposed a cup-shaped catching or intercepting device 6, and this device is namely preferably suspended from the nozzle I by means 01' supports I, in order that the cup 6 may be independent of any motion of the chill mold 2 that may occur. The cup 6 is likewise provided with a cooling jacket 8, to which the cooling medium is delivered through the pipe 8, while it flows out again through the pipe I8.

As a consequence there is during the casting not only a cooling action from the outside through the walls of the chill mold 2, but there is also a cooling action exerted from the inside on the fluid casting head through the cooling jacket 8 of the cup 6, so that rapid solidification occurs in the center of the entire cross section as well. The solidification process may consequently be controlled precisely, through the regulation and proper selection of the cooling medium in the cooling jackets 2 and 8.

If it should not be desired that the cooling action of the cooling jacket 8 of the cup 6 inward ly on the contents of the cup have a more or less strong efiect, then heat dissipation may be prevented in that the inner wall of the cup 6 is made of a less heat-conducting material than the outer wall, or else a special insulating medium may be inserted at this place.

On the other hand, a construction like Figure 2 may be chosen, in which the cup 8 has three annular walls, so that two chambers II and I2 are formed about the side walls and bottom of the cup 6. These chambers II and I2 are connected to separate pipe inflow lines I3, I4 and outflow lines I5, IS. A cooling medium is conveyed through the pipes I3, I6 and the outer jacket I2, which, as in the first example of construction, cools the melt in the middle of the mold as well, so that the solidification process may thereby be controlled. On the other hand, a heating medium is conveyed through the pipes I4, I5and the inner jacket II, so as to maintain the melt that has just flowed into the cup 6 at the most favorable temperature, and to protect it with certainty against the influence of the outer cooling jacket I2. With this construction it is advantageous if the inner and outer walls of the cup 6 consist of material that conducts heat well; while the middle wall II on the contrary is made of insulating material. With such an arrangement, we may not onlyregulate the heat dissipation, and thereby the solidflcation process, but favorable conditions may also be created for the newly inflowing molten metal. It is in this case advantageous to taper the outer wall of the cup down, in order to make it possible for the solidifying melt to free itself from the cup more easily.

0n the other hand, thecooling jacket 8 may be provided only at the bottom, as is shown in Figure 4, so that the side wall of the cup has no cooling.

As Figure 5 shows, the intercepting device does not need to be cup-shaped at all. The intercepting device, whose chief function is to alter the direction of the melt that is poured out, in

- this case consists of only one plate 6, so that the molten metal flowing out of the nozzie I on to it is diverted sideways. The plate 6 is however provided on its under side with a cooling jacket I8, with inflow and outflow pipes I8, 20 so that a cooling medium may be sent through the cooling cup 8 is formed similarly to the example of Figure 1; that is, with a cooling jacket 8 round its side and bottom, which is connected with the inlet and-outlet pipes 8 and II respectively. In this.

case a special cooling contrivance 2| is inserted inside the cup 6; and it consists of curved walls and guide plates, so that the molten metal flowing out of the nozzle I into the interior of the cup 6 is compelled to flow a greater distance in intimate contact with the curved metal plates, before it emerges'at 22 and is able to reach the chill mold from there. The curved plates form the sealing arrangement of a chamber, to which heating or cooling mediums may'be supplied through the pipe 23 as required, while the pipe 24 serves for the outflow. In this wise provision cannot only be made for accurate control of the solidification .by cooling the material that is already in the fluid head, but also by regulation of the temperature of the inflowing new material.

Figure 7 shows a similar arrangement; with the difference however that in this case the curved plates of the chamber 2I are disposed horizontally instead of vertically. Although in this arrangement no special cooling jacket is shown, one could naturally also be applied.

Figure 8 shows a construction similar to Figure 5; that is, with a platform-like intercepting or diverting device 6 with a cooling jacket I8. In

order to secure uniform distribution in all directions of the molten metal emerging from the nozzle I, a special, possibly conical, distributor 25 is disposed upon the plate 8, by means of which it is also possible to prevent the newly inflowing molten metal from being too greatly cooled by too long contact with the cooled plate 6.

Figure 9 shows a similar arrangement, with a distributor 25 on the bottom of a cup-shaped catching or intercepting device 8. As maybe seen from Figure 10, this distributor 25 may also be connected with the cooling jacket 8, so that, its upper surface, with which the molten metal flrst comes into contact, may be maintained at a .determined temperature. t a

. As has already been shown in Figures-3 :and4, it is not requisite that the coolin'g ijacket shall extend over the entire wall of theicup. A further example of this is given in Figure 11, in which the cooling jacket 28 extends only to a certain height of the cup wall. There are then disposed above the cooling .jacket 28 channels 28 and 30,

which run from the inside of the cup 6 to the outside, through which channels the molten metal which is delivered through the nozzle l is able to flow out. As may be seen from Figure 11, the channels may be set at varying degrees of inclination, in order to get varying degrees of outflow.

The same thing may be procured by branching the outflow channels 29, 30 off at different heights of the cup interior, as is shown by Figure 12.

Figures 13, 14 and 15 furthermore show that the outflow channels 29, 30 may be distributed uniformly or non-uniformly around the periphery of the cup 6, in order to obtain special outflows and directions, according to requirements; and in order in this wise also to be able to provide for as uniform temperature regulation as possible.

I claim as my invention:

1. Apparatus for continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing the molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting plate below the outlet of the supply pipe but above the solidified casting, said plate having interior hollow spaces entirely covered by the liquid molten metal in the mold, and conduits which run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal.

2. Apparatus for continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing the molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting cup below the outlet of the supply pipe but above the solidified casting, said cup having interior hollow spaces entirely covered by the liquid molten metal in the mold, and conduits that run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal.

3. Apparatus for continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing the molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting plate below the outlet of the supply pipe but above the solidified casting, said plate having interior hollow spaces entirely covered by the liquid molten metal in the mold, one or more of the walls of the plate being corrugated in sinuous form to increase the surface area thereof, and conduits that run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal.

4. Apparatus for continuous casting of metals and metal alloys, comprising a metal chill mold with a passage through it, a pipe for introducing the molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting cup below the outlet of the supply pipe but above the solidifled casting, said cup having interior hollow spaces entirely covered by the liquid molten metal in the mold, one or more of the walls of the cup being corrugated in sinuous form to increase the surface area thereof, arid conduits that run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal.

5. Apparatus for the continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting cup below the outlet of the supply pipe but above the solidified casting, said cup having interior hollow spaces entirely covered by the liquid molten metal in the mold, the walls of the said cup, along which the fresh molten metal flows, being corrugated in sinuous form, in order to make the heat transmitting surface as large as possible, and conduits that run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal.

6. Apparatus for the continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting plate below the outlet of the supply pipe but above the solidified casting, said plate having interior hollow spaces entirely covered by the liquid molten metal in the mold, and conduits that run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal, and a conical distributor on the wall opposite the inflow pipe for the molten metal arranged with its apex opposite the outlet of the inflow pipe.

7. Apparatus for the continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting cup below the outlet of the supply pipe but above the solidified casting, said cup having interior hollow spaces entirely covered by the liquid molten metal in the mold, and conduits that run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal, and a conical distributor on the wall opposite the inflow pipe for the molten metal arranged with its apex opposite the outlet of the inflow pipe.

8. Apparatus according to claim 6, in which the inner surface of the conical distributor communicates with the hollow space of the deflecting plate.

9. Apparatus according to claim '7, in which the inner surface of the conical distributor communicates with the hollow space of the deflecting cup.

10. Apparatus for the continuous casting of metals and metal alloys, comprising an open metal chill mold with a passage through it, a pipe for introducing molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting cup below the outlet of the supply pipe but above the solidified casting, said cup having inner and outer walls between which lie hollow spaces entirely covered by the liquid molten metal in the mold, conduits which run from the said introducing molten metal into the mold, the outlet end of said pipe being immersed in the liquid metal in the mold, a multiple-walled deflecting cup below the outlet of the supply pipe but above the solidified casting, said cup having inner and outer walls between which lie hollow spaces entirely covered by the liquid molten metal in the mold, conduits which run from the said hollow spaces to the exterior of the mold, in order to be capable of conveying into and out of the hollow spaces a medium for regulating the temperature of the liquid metal, the outer walls of the said cup terminating at a point below the upper edge of the inner wall of the cup, and channels extending outwardly from the interior of the cup, said channels having varying angles of inclination relatively to the cup wall.

12. Process for the continuous casting of metals and metal alloys, consisting of discharging the liquid molten metal, at a speed commensurate with the speed of solidification, into the upper part of an open ended chill mold at a point below the surface of the molten metal head in said mold and substantially centrally thereof, defleeting the discharged stream of infiowing metal also at a point below the said surface, and cooling the infiowing metal at the point where the stream is deflected to prepare the liquid metal for uniform'solidification below said cooling point.

SIEGFRIED J UNGHANS. 

